The present invention relates to apparatus for pressure testing of sealed packages, and particularly to apparatus for burst testing and leakage testing of flexible sealed packages such as used for packaging food products, cosmetics and sterile medical supplies and equipment.
Normal manufacturing quality control protocols require the routine testing of samples of packaged items to assure that production packaging equipment is properly adjusted and operating. For a sealed package such testing may involve pressurizing a package to determine the pressure at which the package bursts, thus providing a measure of seal strength, or may involve pressurizing a package and measuring the rate at which the package leaks, thus providing a measure of seal integrity. In either case, a pressurizing needle or conduit must enter the package to provide pressure, and a second needle or conduit may be required to measure the total internal pressure. Any such conduit must seal against the package.
U.S. Pat. No. 4,205,551 shows one prior art approach to providing entry of a pressure conduit to a sealed package, in which a resilient press member is urged against a package and pressurizing needle to seal the entry point and the lower portion of the package against leakage during testing. The press member, however, may clamp off the upper half of the package, with the result that the device effectively tests only one-half the package. Another prior art device employs a pressure supplying needle surrounded by a suction-cup shaped collar. When the needle penetrates a semi-rigid package, the cup presses against the surrounding package face to seal the area about the needle's entry point. This device is used in connection with a testing jig which urges the assembly against the package and holds it tight during testing.